Reversible propeller



July 29, 1952 R. E. BELL REVERSIBLE PROPELLER Filed Sept. 20, 1947IIIIIIIII) IN VENTOR ROSS EARL BELL.

AT TORNEV Patented July 29, 1952 REYEYRSIBLE mbaaa. j

' p Ross EarbBell,VancouyerfBritish Columbia, Canada-* Amati September 9t1$aiflNW309} 1 IGlaim. (Oldie-13 311 V My invention relates toimprovements in optimum efficiency from a reversible propeller whenoperating in forward and reverse directions and to prevent drag in thesedirections and also when the propeller is operating in neutral and inconsequence nearly all of such propellers are less eflicient inoperation in every one of their running positions than the conventionalsolid propeller.

In view of the above objection, the present invention is designed to bemost efiectively stream lined and so constructed generally that itsefficiency is equal to the conventional solid propeller when set tooperate in a forward direction and to allow the loss of efiiciency whichis now unavoidable in reversible propellers, to be taken when saidpropeller is set to run in reverse direction, or when high efficiency isnot essential.

Referring to the drawings:

Fig. 1 is a front elevational view of the invention.

Figs. 2, 3 and 4 are transverse sectional views of the blades taken onthe lines 2-2; 3-3 and 4-4 of Figure 1 respectively.

Fig. 5 is a sectional detail view of the pivotal mounting of each blade.

Fig. 6 is a sectional view of the propeller hub.

Figs. 7, 8 and 9 are side elevational views of the propeller in forward,neutral and reverse positions respectively.

In the drawings like characters of reference indicate correspondingparts in each figure.

The numeral N indicates generally a propeller shaft upon which a hub I2is secured. The hub I2 is provided with a cylindrical portion I3 and atapering trailing end I4. Extending radially from the portion I3 of thehub I2 are pivot pins I5 having a cylindrical bearing portion I6, athread I1 and a reduced stem portion l8, and on each of the pivot pinsI5 a propeller blade 2| is fitted.

Each blade 20 has an inner face 2| which lies in a plane substantiallytouching the outer peripheral wall of the hub I2 and is drilledoutwardly from said inner face with a hole 23 having an inner bore 24and a counterbore 25 and a thread 26 between said bores which is adaptedto freely receive the thread I'I. Each blade 2| is screwed onto itspivot pin I5 to prevent substantial endwise movement and to be rockinglysupported on said pin with the cylindrical bearing portion journalled inthe counterbore 25 of the hole 23 and the stem portion I8 journalledwithin the inner bore 24 of said pivot pin I5. Each blade is fitted witha bolt 21 which extends from its inner face and is disposed to the rearor toward the trailing edge of said blade. The blades are stream linedin cross section, as shown in Figures 2, 3 and 4, with their forwardfaces convexed transversely and their rear faces lying in substantiallythe plane of the chords of the 7 sections shown.

Slidably mounted upon the shaft II is a hub shell 30 having tangentialwings 3|, each of which conform substantially to the rear part of theinner face 2| of the blade. The wings are slotted inwardly from theirouter ends as at 32 to embrace the bolts 21. The hub shell 3| is fittedto a sleeve 34 which is iournalled in suitable bearings, not shown, andsaid sleeve surrounds the propeller shaft I I to rotate therewith.

Longitudinal slots 35 are formed in the hub shell 30 which straddle thepivot pins I5, so that when the said hub shell is moved rearwardly alongthe hub, the wings 3| through the bolts,

21. rock the blades 2| about the pivot pins I5 until said pivot pins aredisposed adjacent the inner ends of the slots 35 and the wings 3| aredirectly aligned with the inner faces 2| of the blades. When the wings3| are so disposed, viz, with their edges parallel to the edges of thefaces 2|, the propeller is adjusted for forward driving and aminimumresistance to rotation is encountered from said wings becausethey are directly behind the said inner faces. As the sleeve 34 is movedforwardly the wings 3| are likewise forwardly moved, so that the forwardedge of each of said wings will be exposed to side thrust from thewater. The movement of the shell in a forward direction will first bringthe forward and trailing edges into a plane parallel to the radial planein which the pivot pins l5 are set, thus restraining them from exertingany thrust lengthwise of the shaft 2. A still further movement of thehub shell 3| in a forward direction will rock the blades to cause thepropeller blades to exert a thrust in a rearward or reverse direction.In the last mentioned position, the side areas of the wings are exposedto their greatest extent and impose a resistance to rotation, but asspeed and optimum propelling pivot pin.

thrust is not necessary in this direction the eiilciency loss isunimportant.

What I claim as my invention is:

A reversible propeller comprising a hub shell and a hub telescopicallymounted therein, said hub having a plurality of radially extending pivotpins, a propeller blade swingingly mounted upon each of said pins, meanson the hub shell for rocking the blades upon their pins in response toendwise movement between the hub shell and the hub, each of said pinshaving a bearing portion at its inner end and at its outer end and athreaded portion between said bearing portions, each of said bladesbeing bored to form journals about the inner and outer bearing portionsand having an internal thread between said journals to fit the thread ofthe pin, said thread forming the sole means for retaining each bladeupon its aoss EARL BELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Number Name Date Bailey Apr. 16, 1878 HainT Nov. 16, 1897 Patrick May 16, 1905 Roper Feb. 4, 1908 Gnaegy Apr. 21,1908 Bowers Jan. 26, 1909 Esson Mar. 11, 1913 Iskols May 2, 1916 BellJan. 10, 1950 FOREIGN PATENTS Country Date France Mar. 17, 1931

